Design and Simulation of a Microstrip Frequency-Scanning Antenna for Millimetre‑Wave Fuze Applications

To satisfy the simultaneous requirements of high gain and wide angular coverage for millimetre‑wave fuzes under large impact‑angle variations, this paper proposes a microstrip frequency‑scanning antenna based on a quasi‑travelling‑wave, series‑fed patch array. The antenna is implemented on Rogers 4350B substrate (εr = 3.5, thickness h = 0.254 mm) and operates over 30–36 GHz. By exploiting the frequency‑dependent phase progression along the series feed, the main beam steers continuously without phase shifters. Full‑wave simulations in HFSS show that the antenna maintains |S11| < −10 dB across the entire band. The E‑plane main beam scans from 48° at 30 GHz to 0° at 36 GHz, providing a 48° frequency‑scanning range; when the 3‑dB beamwidth is included, the effective detection‑angle coverage reaches approximately 74°. The simulated gain remains stable above 10.5 dBi, peaking at about 11.6 dBi near 35 GHz. With a low‑profile, planar structure (overall size ≈ 20 mm × 10 mm) and no additional terminal load, the proposed design offers a compact solution for fuze antennas that require broad angular coverage and robust gain in the 30–36GHz.